Think about the last time you bought a television. Chances are it was bigger, sharper, and cheaper than the one your parents owned. Now think about your last haircut. The barber used scissors, a comb, and clippers, and it took about twenty minutes. That's roughly how long it took in 1960. Yet the price has climbed well beyond inflation.

This looks like a puzzle. If nothing about the haircut has changed, why should it cost more? The answer has a name: Baumol's cost disease. Economist William Baumol described it in the 1960s. Once you understand it, you'll notice it everywhere, from restaurant bills to school fees.

Economists use the word productivity to mean how much a worker produces in an hour. In some industries, productivity has soared. A factory worker today, supported by robots and automated assembly lines, can turn out many times more goods per hour than a worker could a few generations ago. Farming has changed the same way. One person with modern machinery can harvest fields that once needed dozens of hands.

Other industries work differently. In a haircut, a piano lesson, or a live concert, the human time is the product. Baumol's favourite example was a string quartet. Playing a Beethoven quartet takes four musicians about as long today as it did in the 1800s. You can't play it twice as fast without ruining it. You also can't give someone a good haircut with half the attention.

So the economy splits into two kinds of work. In one kind, technology keeps multiplying what each person can make. In the other, output per hour barely moves. Teachers, nurses, chefs, and barbers can use better tools. But the core of their work still needs a person who is present and paying attention for a fixed stretch of time.

Takeaway

Some work gets faster because machines take on more of it. Other work stays slow because the human time is the very thing being bought.

Here is where it gets interesting. If barbers aren't cutting hair any faster, you might expect their pay to stay flat. It hasn't. Barbers today earn far more, even after adjusting for inflation, than barbers did decades ago. Why would their wages rise when their productivity didn't?

The answer is competition for workers. As factories, offices, and tech companies became more productive, they could afford to pay higher wages. That raised what economists call the opportunity cost of being a barber, which is the income you give up by choosing this job instead of another. Suppose barbering still paid 1960 wages while warehouse and office jobs paid far more. People would stop becoming barbers. Shops would struggle to hire, and the shops that remained would have to raise pay to keep their staff.

So the rest of the economy pulls barbers' wages upward, even though barbers aren't working any faster. Wages are the biggest cost of a haircut, so the price has to rise too. The barber isn't charging more because of greed or slowness. The barber is charging more because everyone else got more productive. The same logic applies to waiters, dental hygienists, and music teachers.

Takeaway

A job's pay depends on more than how productive that job is. It also depends on what else the worker could be doing instead.

It's easy to look at rising costs for haircuts, childcare, or university tuition and assume something has gone wrong. Maybe there is waste, or someone is taking advantage. Sometimes that's true. But Baumol's insight points to another possibility. These prices may rise because society is getting richer, not poorer.

Consider what that means. Factories and farms became very productive, so food, clothing, and electronics now take up a smaller share of most budgets than they once did. That frees up money to spend on services. Your own wage has also risen for the same reasons the barber's has. So a pricier haircut is still within reach. Society as a whole can afford cheap gadgets and more expensive services at the same time, because total output has grown.

This doesn't mean every high price is harmless. Services that can't speed up will take a growing share of spending. That puts real pressure on household budgets and public finances, especially for health care and education. But it does change the question. Instead of asking why services are getting so expensive, we might ask what it means that goods have become so cheap.

Takeaway

Expensive services and cheap gadgets can be two sides of the same coin. They describe a society that has become very good at making things and still values what only people can do.

Baumol's cost disease explains a puzzle hiding in plain sight. When some industries become much more productive, wages rise across the whole economy. Industries that can't speed up still have to pay those wages, so their prices climb.

Once you know the pattern, you'll spot it often. Compare a restaurant meal with a microwave, a concert ticket with a speaker, or a tutor with a textbook. Ask whether human time is the product, and the price usually makes sense.